preserve product identity in manual search

services/search/core.py

@@ -237,6 +237,28 @@ def _result_has_query_overlap(query: str, result: dict) -> bool:
         )
     result_tokens = set(re.findall(r"[a-z0-9]+", text))
 
+    document_cues = {
+        "manual", "manuals", "guide", "guides", "instructions", "instruction",
+        "documentation", "docs", "pdf", "handbook",
+    }
+    if query_tokens & document_cues:
+        entity_fillers = _SEARCH_QUERY_FILLER | document_cues | {
+            "english", "operator", "owner", "owners", "user", "installation",
+        }
+        ordered_query_tokens = re.findall(r"[a-z0-9]+", str(query or "").lower())
+        entity_terms = [
+            token for token in ordered_query_tokens
+            if token not in entity_fillers and not token.isdigit()
+        ]
+        # Product/manual lookups are especially vulnerable to homonyms. A
+        # result matching only the generic product word and "manual" is not
+        # evidence for the named brand/entity in the request.
+        if entity_terms and entity_terms[0] not in result_tokens:
+            return False
+        model_numbers = {token for token in ordered_query_tokens if token.isdigit()}
+        if model_numbers and not model_numbers.issubset(result_tokens):
+            return False
+
     def lexical_root(word: str) -> str:
         for suffix in ("ation", "ition", "ence", "ance", "ment", "ents", "ent", "ant", "ing", "ed", "es", "s"):
             if word.endswith(suffix) and len(word) - len(suffix) >= 6:

tests/test_search_empty_query_relaxation.py

@@ -23,6 +23,20 @@ def test_empty_document_search_relaxes_scaffolding_then_entity():
     ]
 
 
+def test_manual_relevance_rejects_homonym_without_brand_and_model():
+    query = 'WIKING Miro 3 English manual official source'
+    assert not core._result_has_query_overlap(query, {
+        'title': 'Miro Appliance User Manuals',
+        'url': 'https://shop.mirohome.com/pages/miro-appliance-user-manuals',
+        'snippet': 'Manuals for Miro humidifiers and air purifiers.',
+    })
+    assert core._result_has_query_overlap(query, {
+        'title': 'WIKING Miro 3 Installation and User Manual',
+        'url': 'https://www.hwam.com/manuals/wiking-miro-3.pdf',
+        'snippet': 'Official English installation and user manual.',
+    })
+
+
 def test_search_uses_entity_relaxation_only_after_exact_queries_are_empty(
     monkeypatch, tmp_path,
 ):